Hello,

I am trying to repair a Dahua NVR4216-4KS2 that is not booting.
The main BIOS/firmware is stored in an SPI flash EEPROM (Winbond 25Q128, labeled as U130 on the PCB).

I have a CH341A programmer and I already attempted the following steps:

1. Identified the correct chip (W25Q128, 3.3V SPI flash).
2. Tried to read the contents with CH341A Programmer software. The dump seems corrupted and I often get the error: “Chip with the contents are in disagreement.”
3. Compared several chip type selections (24Cxx and 25Qxx families) to confirm it is indeed a 25 series SPI

...

Hello everyone,

My name is Brayan and I recently joined the Badcaps community. I work in IT support and often deal with hardware repairs, especially DVRs, NVRs, and PCs.

I joined this forum because I know there are many experienced members here when it comes to BIOS/EEPROM dumps and board-level repairs, which is an area I want to learn more about and contribute to when possible.

Looking forward to sharing and learning with all of you.

Best regards,
Brayan...